Internal combustion engine



17, 1940- Q D. s. LORRAINE ET AL 2,224,973

INTERNAL COMBUSTION ENGINE Filed May 2, 1938 Fla. 1

\ INVENTOR. F/ 6. Z DAVAO G. LORRAWE FRED N YOUNG A TTORNEY Patented Dec. 17, 1940 UNITED STATES INTERNAL COMBUSTION ENGINE David a. Lorraine, Glendale, Calif., and Fred M.

Young e, Wis.

Application May 2, 1938, Serial No. 205,518

3 Claims. (01. 123- 191) The present invention relates to an engine having two unitary pistons and two compression chambers, one for high or secondary compression and the other for normal or primary compression. The high compression piston and chamber are concentric with the normal piston and its chamber and has a spark plug or other means for igniting the highly compressed gas therein. The gasses in the primary space will be ignited by 10 the burning gasses in the secondary chamber after being uncovered by its piston. Thus we provide primary and secondary compression and secondary and primary ignition in the order given.

A further object of the present invention is to confine the high compression piston to a relatively small area making it possible to use very high compression and initial pressure without subjecting the engine to harmful strains or vibrations.

A still further object of the present invention is to provide means whereby low grade fuel may be used successfully on small units as well as large.

Another object is to provide an engine which is highly eflicient, light, quiet running and adaptable to the various service conditions to which engines of the class are subjected.

In the present invention if preignltion takes place it will not be a serious matter, because of the limited area of the secondary piston and furthermore, ignition under normal operating conditions need not be so exactly timed for obvious reasons. Ignition may be brought about by means of a spark plug, compression heat or fuel injection and the exact time of ignition is arbitrary because the secondary compression pressure is secured too quickly to be very sensitive to the time of ignition. Clearly when liquid fuel is injected the injection may be timed to begin at or any time after the secondary piston enters its chamber and in any event the action would be somewhat similar to the action of an engine having an ignition pocket with a reduced connection to the compression chamber.

It will be noted after scrutinizing the drawing that the desired objects are accomplished v without adding materially to the cost of the engine. And furthermore, in view of the very high compression and small piston area of the secondary device, the engine will operate more successfully under all-load conditions and provide a more uniform idling action than is possible in as conventional engines of the class'.-

One of the results of the present invention is that while conventional high compression engines add considerable to the necessary weight of the engine, in the present design verylittle or no additional weight is necessary although considerable more power may be developed.

To these and other useful ends our invention consists 'of parts, combinations of parts or their equivalents and mode of operation, as hereinafter described and claimed and shown in the accomo panying drawing in which:

Fig. 1 is a transverse fractional sectional view of an L-head engine equipped with our invention.

Fig. 2 is a transverse fractional sectional view of a T-head engine equipped with our invention. 15

Fig. 3 is a fractional drawing illustrating .a modification.

It will be understood that various other arrangements of valves may be used in connection with our invention. For example, we may make 9 use of valves in the head system, or other changes made in the design which may be required to meet various engine sizes and operating requirements or a two cycle engine may obviously be 25 equipped with our invention.

As thus illustrated, the cylinder in Figure 1 is designated in its entirety by reference character A and the cylinder in-Figure 2 is designated in its entirety by reference character B. 3

In Flgure 1 the piston is designated by numeral III having a piston pin ll, connecting rod l2 and rings IS. on the upper end of piston III we concentrically position a circular projection or secondary piston ll being of a diameter which 35 will present an end area considerable less than the remaining area of the primary piston.

The cylinder is provided with an L-head valve system, the exhaust valve being designated by reference characters ID. The other, or inlet valve (not shown), is positioned adjacent this exhaust valve as is conventional in engines of the class.

We provide a cylinder head I! which is conveniently secured to the cylinder by means of bolts 20. A conventional gasket 2| is supplied with which to form a pressure tight joint between the head and cylinder. In the design shown, a valve chamber 22 is provided as is the custom in engines of the type.

' We provide a chamber 25 in head I9 which is 50 adapted to receive piston H as illustrated. Member 25 is made to closely but freely embrace member I4 and the depth of this chamber being arranged to provide a compression space 26 whereby maximum compression pressure in this chamber may be several times greater than the compression pressure in chambers 22 and 21.

In th present design it will be understood that compression pressure in chamber 21 may be conventional for engines of the class but the compression in chamber 26 is preferably considerablegreater in some designs, perhaps three or four times greater than the primary compression.

We provide a spark plug 30 which is preferably centrally positioned as illustrated. The lowest point of the spark plug is practically on the'same plane as th top surface of chamber 25.

In the design shown, it will be seen that for example if the compression in space 21 reached say 80 pounds gage pressure the diameter of piston I 4 and the compression space 26 may be' arranged if desired to provide a compression in chamber 26 of say 300 pounds per sq. inch or more, whereby the enginemay be operated on the Diesel principle. However, because of the area of piston I4, the effect of the explosion or sudden combustion of gasses in chamber 26 will not be harmful to a standard designed engine.

Thus it will be seen that the power capacity of the engine may be considerably increased without materially increasing the weight of the engine.

One of the principal advantages of the present invention is that maximum efficiency is obtained by limiting the secondary compression chamber to a small area. The action of piston as it approaches chamber 21 will be to cause turbu-, lence in both compression spaces. And during the downward stroke at the moment piston l4. passes from chamber 25 the outward rush of the burning gasses into chamber 21 will cause violent turbulence of the gasses in this chamber and at the same time the gasses in this chamber will be ignited or if 'the engine is operating on the fuel injection principle, the rich hot gasses will sweep into chamber 21 and combustion will be completed by mixing with the air in this chamber. Thus there are two stages of compression and two ignition stages.

It will be noted, however, that the ignition of the gasses in the secondary chamber2l will take place early in the downward stroke whereby combustion will be completed before the end of the stroke by reason of the primary and secondary igniting action. Thus it will be seen that a number of factors in our invention cooperate to provide a light weight engine which will give maximum power and maximum fuel economy.

In Figure 2 we illustrate a T-head engine equipped with our invention. In this design the operation will be exactly the same as'the operation of the design shown in Figure 1.

We illustrate in the drawing a cylinder 40 having a piston ll, a connecting rod 42, a concentric circular projection 42 on the piston and a chamber in the cylinder head which corresponds to chamber 25 in Figure 1. Valve 44 may be considered the inlet valve and valve 45 may be considered the exhaust valve. A compression space '48 is provided above the inlet valve and a compression space 41 is provided above the exhaust valve. It will be noted that in this design the piston 41 when in its uppermost position provides a narrow compression space 48 thus when the hot gasses are released from the primary compression space they will act exactly as' described in connection with Figure 1.

It will be understood that in designing the engine for various purposes and of various sizes many changes in the details may be made, and many changes made in the proportions of the primary and secondary compression spaces depending largely on the speed and size of the engine and to some extent upon the fuel which the engine is designed to use. x

In Figure} we illustrate fractionally an engine cylinder 50 having a piston II upon which is mounted similar to the other views a secondary piston 52. A head BI is provided having a chamber I4 into which piston I2 moves as in the other designs. The design provides a secondary compression space II and a primary compression space 56. Numeral II designates the discharge end of a fuel inJecting nozzle the general design being suitable for a two cycle engine. It will be understood, however, that instead of the fuel injecting nozzle 51 a spark plug may be substituted.

It will be understood that the fuel injecting nozzle 51 may be substituted for spark plugs 30 in Figures 1 and 2. Thus clearly our invention is adaptable to either the -.two cycle or four cycle principle. I

Clearly many minor detail changes may be made without departing from the spirit and scope of the present invention as recited in the appended claims.

Having .thus shown and described our inven-- tion, we claim:

1. An internal combustion engine of the car- .buretor served class described, having a cylinder and piston therein, a compression space and inlet and outlet valves therefor, including in combination therewith a relatively small concentrically positioned secondary piston on said first piston, a secondary chamber in the head of said engine adapted to register with said secondary piston and to closely fit therearound, said secondary piston having a length' whereby it will enter the secondary chamber after said first piston has completed the major part of its compression stroke and having a length cooperating with the length of the secondary chamber whereby the mixture therein reaches a pressure considerable greater than the engine compression, a spark plug communicating with the compression space in said secondary chamber whereby the mixture in said secondary chamber is ignited and whereby the mixture in the engine compression chamber will be ignited by the flame from the secondary chamber after it is uncovered by said secondary piston. v 2. An internal combustion engine of the class described, having a cylinder and a piston therein, a compression space and means to supply a combustible mixture to said compression space, including in combination therewith a relatively small concentrically 'posi-tioned secondary piston on said first piston, a secondary chamber in the head of said engine adapted to register with said secondary piston and to closely fit .therearound, said secondary piston having a length whereby it will enter the secondary chamber after said first piston has completed the major part of its compression stroke and having a length cooperating with the length of the secondary chamber whereby the mixture therein reaches a pressure considerably greater than the engine compression, a spark plug communicating with .the compression space in said secondary chamber whereby the mixture in said secondary chamber is ignited and whereby the mixture in the engine compression chamber will be ignited by the flame from the secondary chamber after itis uncovered by said secondary piston.

3. An internal combustion engine of the class described, having a cylinder and a piston therein, a compression space and means to supply a combustible mixture to said compression space. including in combination therewith a relatively small concentrically positioned secondary piston on said first piston, a secondary chamber in the head of said engine adapted to register with said secondary piston and to closely fit therearound, said secondary piston having a length whereby it will enter the secondary chamber after said first piston has completed the major part of its compression stroke, and having a. length cooperating with the length of the secondary chamber where- .by-the mixture therein reaches a. pressure considerably greater than the engine compression, means adapted to ignite the mixture in said secondary chamber whereby the mixture in the engine compression chamber will be ignited by the flame from the secondary chamber after it is uncovered by said secondary piston.

. DAVID G. LORRAINE. FRED M. YOUNG. 

